▎ 摘　　要

NOVELTY - A functionalized graphene oxide composite film is obtained by crosslinking graphene oxide with polyoxyethylene diamine and forming the crosslinked product on microfiltration membrane substrate by vacuum filtration. The size of graphene oxide sheet is 500 nm-10 mu m. The molecular weight of polyoxyethylene diamine is 500-5000. USE - Functionalized graphene oxide composite film is used for gas separation, carbon dioxide-methane separation and carbon dioxide-nitrogen separation (all claimed). ADVANTAGE - The functionalized graphene oxide composite film has thickness of less than 10 nm, molecular weight of 1000, high carbon dioxide permeation flux of 220 GPU, carbon dioxide-methane selectivity value of 42, carbon dioxide-nitrogen selectivity value of 55 and excellent comprehensive performance, and the distance between graphite sheets is adjustable. The preparation method is simple. DETAILED DESCRIPTION - An INDEPENDENT CLAIM is included for functionalized graphene oxide composite film.